Drilling machine



June 26, 1928. 1,674,867

F, K. KRAG DRILLING MACHINE Filed oct. 1492s fm* l wm l l /H- W) 5f 35i Lf y f ,i j, y

l3nt-entend une 26, i923.

i were am s t t il telg lrianne'. n. KRAG, or onroaeo, rumors.

DRILLING MACHINE.

Application filed October 3, 1923. Serial No. 666,320.

improve the construction and operation of drill presses.

Another object of my invention is vto provide means whereby a wider range'of Work can be practically and successfully performed. 1

Again l aim to provide a drill press construction wherewith very fine and accuratel work such for example as providing pilot drillings or spots can bemade quiclrly and easily and also accurately placed holes for other purposes, all by means of an ordinary drill press, thus saving much time and expense and obviating the necessity of having a special machine for such work.

My invention consists generally in a drilling machine and in an attachment therefor comprising such an arrangement, form7 and construction that the above named objects together with others that will appear hereinafter are attainable. MyA invention will be more readily understood by reference to thev accompanying drawings which illustrate what l consider, at the present time,to be the preferred embodiment thereof.

In said drawings:

Fig. 1 is a side elevation of a portion of a drilling machine embodying my invention, part thereof being broken away better to disclose, the interior construction.

Fig. 2 is a perspective view of the drill guide member detached from the machine; and

Fio. 3 is a view substantially on the line 3 3 of Fig. 1, but upon an enlarged scale.

ln machine shop practice it is frequently necessary to provide pilot drillings or spots for use in drilling larger holes and this work has either required special machinery o1' has been a slow, laborous and expensive operation. Again at times, in general machine shop work it becomes necessary to drill very line and very accurately spaced holes. Unless special machinery he provided such a job requires very accurate plan ning and a skillful operator, and at best is a slow and expensive operation. ln many machine shops such work is done at rather infrequent intervals so that special and expensive machinery is not available. I have provided a very simple and inexpensive construction which every shop can alford to install. i 4

Referring now to the drawingsfor the details of construction, 1, represents the frame which may .take the form of the usual drill press frame and is provided with spaced bearings?J and 3 in which there is rotatedly mounted ashaft or spindle 4l. Feathered to the shaft 4 is a. pulley 5 so that the desired rotation can be imparted from Aany suitable source by means of a belt y(not shown). The

shaft et extends through a sleeve 6 and is connected tothe tool holder 7 which, in this instance, is provided with the ,usual chuck 8 for gripping the tool or drill 9. At opposite ends of the sleeve t3 will ybe found'stop rings 10 and 11 which prevent relative longitudinal movementof the shaft et and the sleeve 6 whilst permitting rotation of the shaft within the sleeve.' The sleeve 6 is provided Awith the usual gear rack 12 which meshes with al pinion 13 that rotatably carried on the shaft lil-. In order to enable convenient rotation of the shaft- 14 and the pinion 13 the usual hand bar or lever =15-is provided. Byk the mechanism thus far described'drill 9 may be moved to and from the work. For :most work the drill` ofthe desired sizefis merely ixed in the chuck and moved downwardly to drill the hole and retracted.

For accurate work and for spotting7 purposes I have provided a drill guide which, as here shown, takes the form of a bell crank lever having a main arm portion 16 and a secondary arm portion 17. The frame of the drill press is cut away as indicated at 18 to accommodate the bell crank member which is obviously mounted therein as by means of the shaft 18. rlhe operative end of the arm portion 16 is bifurcated as indicated at 19 and is provided with a split bushing 20 and an endless bushing 21. The endless bushing 21 is of a size accurately to tit the drill 9 so that the end of the drill is guided and steadied against any tendency to spring or become disaligned when the drill engages the work. An ordinary bolt 22 is provided to enable convenient clamping of the parts. Then a different sized drill is to be used the bushingl 2l is removed and another one of the proper size inserted. The bell crank is very accurately formed so that when it is in the full line position shown in Fig. 1 the aXis of the bushing 21 will be in perfect alignment with the anis of the drill 9. In order to lock the drill guide in fifi this position the arm portion 17 is provided with a hole 23 through which a locking pin 24 passes, the frame of the drill press being provided with suitable holes for the rece tion of the locking pin 24. When the drill guide is not required the locking pin 24 is removed and the bell crank swung to the dotted line position, shown in Fig. 1, and

the locking pin 2/1 replaced in the hole 25 provided in the arm portion 16. I/Vhen the bell crank is in the dotted lineposition the drill press, to all intents and purposes, becomes an ordinary drill press and can be used as conveniently* to perform all of the operations to which a drill press is adapted. At the same time it can almost instantly be converted into va machine for very accurately drilling pilot holes or other holes which must be so positioned. f

rlfhe many advantages of my invention will be apparent to those skilled in the art without further comment.

I claim:

1. In a. drilling machine, a frame includ- 'i ing a curved portion having a viront open ing recess therein, a drill holder carried by the frame, a bell crank shaped drill guide member including a shortv arm and a long arm curved in accordance with the curved portion ofthe frame, said lever -being pivoted at the junction of said arms in the recess in the trame so that the long arm is swing able outwardly to bring a portion thereof s in axial alignment with the drill holder and means carried by the curved portion of the frame for holding the drill guide member rmly in its operative position with respect to the drill holder.

2. In a drilling machine, a frame having a recess therein,a drill holder carried by the frame and a drill guide member pivotally the frame and a drill guide member pivotally mounted in the recess in the frame, and including relatively short and long angularly disposed arms, each having any opening therein, a drill guide carried at one end of the long arm, said drill guide member being swingable trom a position entirely within said recess to a position wherein the long arm is entirely without said recess with the drill guide in alignment with the drill holder` and a pin adapted to be inserted through openings in the recessed portions of the trame and into the opening in either arm to lock said drill guide member in either of its positions.

In testimony whereof, I have hereunto set my hand, this 25th day of September, 1923.

FRANZ K. KRAG. 

